Step 1: Compost Preparation

Substrate materials should be chopped into small pieces and wet before composting it.
The composted substrate must be pasteurized before being used for spawning. Compost
preparation may be done outdoors or indoors provided that proper aeration is present. Major
facilities required for successful compost preparation are,
1. A concrete floor to prepare the substrate materials
2. A compost turner to aerate and water the substrate materials
3. A tractor-loader to move the substrate materials to the compost turner
4. Pitchforks to turn the compost piles in the compost turner
The substrate materials are chopped into fine pieces and mixed well with nitrogen
supplements and gypsum before wetting them and stacked in rectangular piles. Nitrogen
supplements such as chicken manure, soybean meals or peanuts are added to increase the
nitrogen content of the compost and gypsum is added to minimize the greasiness compost.
Gypsum is added @ 40 lbs. per ton of dry ingredients.
Compost piles are made with tight sides and a loose center for facilitating proper
aeration. A recommended size of a compost pile is 5 to 6 feet wide, 5 to 6 feet high, and length
as per the requirement. Care should be taken that the compost piles should not be stacked very
compact, because air cannot move freely through densely packed compost piles and as a result
an anaerobic environment will develop which is detrimental for successful compost preparation
process.
Well-prepared substrate materials are then put through a compost turner and water is
sprayed at an interval of two days as substrate materials move through the compost turner. As a
rule, initial watering is done after there is sufficient heat build-up (145° to 170°F) within the
compost piles and watering is done up to the point of leaching while compost pile is turned slowly using pitchforks. After this initial watering, little water is required during the remaining
period of composting process. Watering and turning compost piles are done simultaneously.
Turning compost piles at regular intervals ensures proper mixing of all the ingredients; proper
aeration and relocates the substrate materials from a cooler to a warmer area within the
compost pile.
While preparing compost, care must be taken to provide adequate moisture, oxygen,
nitrogen, and carbohydrates or else the composting process will fail. Therefore it is essential
that water, gypsum and nitrogen supplements are added at regular intervals and the compost
pile is adequately aerated as it moves through the compost turner.
Aerobic fermentation of compost begins after a few days and normally a composting
cycle lasts from 7 to 14 days depending on the nature of the substrate materials used. Since
ammonia and carbon dioxide are produced during composting, a strong smell is associated with
composting process. Due to the desirable chemical changes that are associated with the
composting process, there are high levels of biological and chemical activity within the
compost. This compost is rich in food materials necessary for mushroom growing and it has
sufficient heat build-up also. The compost temperatures may reach up to 170° to 180°F during
the second and third turnings if desirable composting conditions are maintained.
Towards the end of the composting process, one last turning of the compost piles is
done and at this time, water is applied generously up to the point of leaching. Watering is an
important process during composting as there is a strong link between watering and the
biological activity of the compost. Nutritional value of the compost is enhanced when there is
sufficient water to build up a favorable temperature within the piles for the enhanced growth
and activity of the beneficial microorganisms. Characteristics of a well-prepared compost are, a) it has a chocolate brown color; b) it is
soft c) it has a moisture content ranging from 68 to 74 percent; and d) it has a strong odor of ammonia